Abstract
Black soybean (BS) is widely thought to prevent or alleviate hair loss, which has been demonstrated by in vitro experiments. However, few clinical studies have directly assessed the effect of BS on hair growth. To assess the safety and efficacy of BS, we administered BS extract to 10 adult patients for 3 months without any other hair products and treatments. The number and diameter of hair lost from washing were examined every 4 weeks. In addition, the participants' satisfaction with their hair condition was also measured using the VAS (1 to 10) before and after treatment. The mean number of lost hair was 140.7 (SD 59.4) at baseline and 38.8 (SD 54.4) after 12 weeks, and the diameter of lost hair was 72.4 µm (SD 11.9) at baseline and 80.4 µm (SD 8.8) after 12 weeks, which indicated a statistically significant improvement (p = 0.002, p = 0.022, paired t-test). The satisfaction score was significantly increased from 6.10 (SD 1.2) to 8.2 (SD 1.1) after 12 weeks. These results suggest that BS extract may promote hair growth and prevent hair loss.